???????
      +--------
TYLUG | WGJTYJT
       -HNQWY
        =====
        GJGWFJ
       -GHTJPH
        ======
         YLPYTT
        -YJUJNP
         ======
         ??????

base: 13
letters: FGHJLMNPQTUWY
difficulty: hard
missing: M